(1) Field of the Invention
The present invention generally relates to acoustic systems and more particularly to underwater sound transmitting or receiving systems having the unique property of having a directional constant beamwidth diffraction pattern over a wide band of frequencies either with or without scanning.
(2) Description of the Prior Art
Many prior art devices in the underwater field have addressed themselves to the problem of providing wide band frequency response so that maximum sound pressure level remains uniform over a wide range of frequencies. The above recited prior art, however, has not addressed itself to the problem of maintaining a constant beamwdith directional diffraction pattern over a wide range of frequencies.